I've been on 200mg (2 x pessaries) nightly of P4 since about week 5 as I had continual light bleeding and spotting, which continued for approx 3 weeks after I started P4.
I was told I could stop using the pessaries at the end of week 12, and as of approx 5 days ago, I decided to only use 100mg nightly. Now I'm down to the last week, I'm going to not use it tonight and prob Wed night. My acupuncturist/naturopath told me to wean, not go cold turkey. My GP didn't offer any advice re: weaning.

I also understand there's not much point using P4 beyond Week 12 as the placenta should be producing all you need.

Congrats on your pregnancy